Safety ignition system for gas burners



March 27, 1962 J. M. ALGINO 3,026,932

SAFETY IGNITION SYSTEM FOR GAS BURNERS Filed Sept. 5, 1958 Q A J') ad m N \g^e w i was:

L. l/ M 3 026 932 SAFETY IGNITION sifsTEMp-FORGAS nURNERs Joseph M. Algino, Chicago, Ill., assignor to The Doie Valve Company, Morton Grove, Ill., a corporation of Iliinois Filed Sept. 5, 1958, Ser. No. 759,234 5 Claims. (Cl. 158-125) This invention relates to an improved safety ignition and control system for gas burners and the like, in which the gas burner is electrically ignited.

A principal object of the invention is to provide a new and improved gas burner safety ignition and control circuit so arranged as to prevent the passage of gas to the burner unless the system is in a safe condition for igninon.

A further object of the invention is to provide a safety igniter and control system for gas burners igniting the burner by an electric spark, in which the ignition device is deenergized upon failure of any of the component parts of the system as well as low or no gas pressure.

Still another object of the invention is to provide a safety ignition and control system utilizing a spark igniter for igniting the gas burner, so arranged as to deenergize the igniter upon lighting of the gas burner and to hold the igniter from being reenergized when the gas flame has gone out, except when the system is in a safe condition for igniting.

A still further object ofthe invention is to provide a safety igniter control circuit for gas burners and the like, in which the burner is supplied with gas through two valves in series, and in which a means is provided to open one of the valves upon energization of the igniter, and other means is provided to hold the valve open as the second valve is open and the system is in a safe condition for ignition of the main gas burner.

Stil another object of the invention isto provide a safety gas igniter and control system in which the burner is ignited by a spark igniter and gas is supplied to the burner through two electrically operated valves, in which at least one of the valves isopened by a solenoid coil energized upon energization of the igniter and is held open by a hold in solenoid coil energized through the contacts of a time delay relay, and deenergized to effect closing of the Valve upon .opening of the time delay relay, effected by failure of the pilot to ignite.

These and other objects of the invention will appear from time to time as the following specication proceeds and with reference to the accompanying drawing wherein:

FIGURE 1 is a diagrammatic view of an automatic safety igniter and gas burner control system constructed in accordance with the invention; and

FIGUREZ is a diagrammatic view, diagrammatically illustrating a modification of the invention.

In the embodiment of theinvention illustrated in the drawing, a main gas line is shown as supplying gas to a gas .burner 11 under the control of two valves 12 and 13, connected in said gas line in series on the supply side of the main gas burner, and. herein shown as being solenoid operated.

An igniter 15, which may be an .electrically energized igniter, such as a spark igniter, a glow coil and the like is positioned adjacent the burner 11 for igniting the burner upon the supply of gas thereto. The igniter 15 is. herein shown as being. a spark igniter and may-be a well known form of spark plug, or may be of any other form effective to ignite the gas issuing from a gas burner.

The igniter 15 is energized through a secondary 16 of a transformer 17, having a primary 18 energized through main power lines 19 and 20 through a normally closed time delay switch 21, a flame detector switch` 22, and adiustable thermostatic switch 23 and a timer switch. 24..

3,026,932 Patented Mar. 27, 1962 The timer switch 24 may be closed upon the setting of the timer to an on position. Said timer switch and the timer for opening said switch at the termination of a predetermined time interval, may be of any -wellknown form, no need not herein be shown or described in detail.

The thermostatic switch 23 is provided to open when the temperature reaches a predetermined value, to deenergize the burner circuit and effect closing of the valves 12 and 13,y and to then close when the temperature has been reduced below this predetermined value. Said thermostatic switch may be adjusted to open at various-desired temperatures and may be of any well known form, and is no part of the present invention so need not herein be shown or described further.

The flame detector switch 22 may also 4be of any well known form, and isillustratively shown as being a bulb and capillary tube type'of thermostatic switch, although it may be a rod and tube type of thermostatic switch or may be of various other forms, effective to open a circuit by the heat of the burner ame. Asrherein shown, a bulb 25 is positioned adjacent the burner in heat sensing relation with respect to the burner flame and is connected with a pressure operated bellows or operator 26 through a capillary tube 27. An expansible liquid or vapor in the bulb 25 may expand within said bulb by the heat of the burner ame to operate the operator 26 and effect opening of the ame detector switch 22 and deenergization of the transformer 18 and spark igniter 15, upon the lighting of the gas issuing from the burner.

The valve 12 is shown as being opened by a solenoid 29 including a solenoid coil 30 and an armature 31.

The valve 13 is shown as being opened by a pull-in solenoid 32 including a pull-in coil 33 and an armature 35.

The valve 13 is shown as being held open by a solenoid coil 36 connected in parallel with the coil 31 and encircling the armature 35 and serving as a holding coil 36. The pull-in coil 33 and the holding coil 36 may be wound on the same cores, if desired.

The time delay relay 21Ymay be of the bi-metal type, heated by a resistor heater coil 37 and opening ina p redetermined time interval, which may be from 45 to 69 seconds, after the energization of the heater coil 37.

The heater coil 37 and pull-in coil 33 are energized through a conductor 39 connected withthe main line conductor@ and through a conductor 40 connecting the heater coil 37 with the pull-in coil 33. A conductor 4l leading from the pull-in coil 33 is connected with a contact 43 of the flame detector switch 22 and is connected with the conductor 20 through the llame detector switch 22, the thermostatic switch `23 and the timer'switch 24;' The heatercoil 37 and the pull-in coil 33 will thus be Ideenergized upon opening of -the flame detector-switch 22 effected by the heat of the pilot flame, or upon opening of the thermostatic switch 23` or the timer switch 24.

The Vsolenoid coil 30 for opening the valve 12, and the holding coil 36 for holding the valve 13 openv are energized through the contacts of the time delay vswitch A21 through a conductor 44 connecting the coils 36 and 36 in parallel, and through aconductor 45 connected with a conductor 46, connected with the conductor 29 through the thermostatic switch 23 and the timer switch 24.Y

The coils 30 and 36 are thus energized upon closing of the timer switch 24 and remain energized as long as.

18 will be energized through the time delay switch 21, the flame detector switch 22, the thermostatic switch 23 and the timer switch 24. This will effect the energization of the spark igniter 15. The heater coil 37 and pull-in coil 33 will also be energized through the flame detector switch 22, the thermostatic switch 23 and the timer switch 24. The valve 13 will then open. At the same time the solenoid coil 30 and the holding coil 36 will be energized through the contacts of the time delay switch 21, the thermostatic switch 23 and the timer switch 24. The two valves 12 and 13 will then open and the burner will ignite, provided there is no failure in any part of the system.

Upon lighting of the burner, the flame detector switch 22 will open in a delayed time interval, which may be in the order of 30 seconds. The heater coil 37 and the pullin coil 33 as well as the transformer 1S will then be deenergized, the holding coil 36 holding the valve 13 open.

In case the burner should fail to ignite, the resistor heater 37 will effect the opening of the time delay switch 21. This will deenergize the transformer 18 and spark igniter 15. It will also deenergize the solenoid coil 30 and the holding coil 36. The valve 12 will then close and the flow of gas to the burner will stop. The pull-in coil 33 and resistor heater 37 will, however, remain energized through the flame detector switch 22, the thermostatic switch 23 and the timer switch 24. The valve 13 will then remain open, but no gas can pass through the burner 11, since the valve 12 is closed.

Failure of the burner to ignite may be due to either a burned out or faulty igniter, a faulty transformer, low or no gas pressure or poor contact pressure at the flame safety switch. In any of these faulty conditions, however, the time delay relay 21 acts as a safety switch to deenergize the igniter and stop the flow of gas to the main burner, and to hold the burner circuit open until the faulty condition has been corrected.

In case the resistor heater 37 should be burned out, when the timer switch 24 is closed, the pull-in coil 33 will not be energized. The coil 30 and the holding coil 36 will, however, be energized, 'but the valve 13 will remain closed and there can be no flow of gas to the main burner until the burned out heater coil has been replaced.

Upon a power interruption due to a power failure, resetting of the timer or the opening of the dryer door, where the circuit may be used for heating a clothes dryer or the like, the holding coil 36 will immediately be deenergized. The valve 13 will then close, If the current flow should be resumed prior to the closing of the flame detector -switch 22, the valve 13 will remain closed blocking the flow of gas to the burner 11. The transformer 18 will also be deenergized. The valve 12 will open as the current flow is resumed. The valve 13, however, will remaln closed until the flame detector switch 22 has moved to its closed position. At this time the transformer 18 will be energized and the valves 12 and 13 will open.

If the llame detector switch 22 should fail to open, the heater coil 37 will effect opening of the time delay switch 21. The transformer 18 and the solenoid coil 30 will then be deenergized. The valve 12 will then close to block the flow of gas to the main burner 11.

If the llame detector switch 22 should fail to reclose upon the completion of a heating cycle, as it is attempted to start a new heating cycle, the solenoid 30 and the holding coil 36 will be energized in the manner previously described. The pull-in coil 33, however, cannot be energized, since the flame safety switch opens the circuit to this coil. The valve 13 then will not open and there will be no flow of gas to the main burner until the flame detector switch 22 closes.

In .the form of the invention illustrated in FIGURE 2, I have shown the same components and same general system as in FIGURE 1. Like part numbers will, therefore, be applied to like parts shown in, FIGURE l, and

new part numbers will only he applied to the new parts.

In the modified form of the invention illustrated in FIGURE 2, the valve 12 is provided with a pull-in coil 49 and a holding coil 50. The two coils 49 and 50 may be like the coils 33 and 36 for the valve 13 and extend about an `armature 51 for the valve 12, to effect opening of the valve 12 and to hold said valve open as the pull-in coil 49 is deenergized.

The pull-in coil 49 is energized through the time delay switch 21, the conductor 44, the conductor 41 and the contact 43 of the flame detector switch 22. The holding coil 50 is energized through the time delay switch 21, the conductor 44, the conductor 45, the thermostatic switch 23 and the timer switch 24.

The two coils 49 and 50 will both be deenergized upon opening of the time delay switch 21. The pull-in coil 49, however, is deenergized when either the time delay switch 21 or the flame detector switch 22 is open. The holding coil 50 will, however, hold the valve 12 open upon opening of the flame detector switch 22, until either the thermostatic switch 23 or the timer switch 24 opens, unless the time delay switch 21 should open due to a failure in the system.

The provision of the individual pull-in coils for each valve, energized and deenergized through different control circuits, and both deenergized upon lighting of the burner, therefore, obviates the possibility of the two valves 12 and 13 sticking open upon a failure in the system.

As an example, where it may be attempted to start the burner circuit and the flame detector switch 22 may not close, due to a failure in this switch, neither of the valves 12 nor 13 could open, since the pull-in coils 49 and 33 are energized through the switch arm of the flame detector switch. Therefore, if dirt should lodge on the seat of the valve 13, the valve 12 would still prevent the leakage of gas to the burner 11. If dirt should lodge on the seat of the valve 12, the valve 13 would prevent the supply of gas to the burner.

The holding coil for the valve 12 is thus an added safety feature, preventing the valve 12 from opening unless or until the flame detector switch 22 is in its closed position and thereby preventing the leakage of gas to the burner where one valve or the other may be held open by dirt on the seat thereof.

It will be understood that various modifications and variations in the present invention may be effected without departing from the spirit and scope of the novel concepts thereof, as defined by the claims appended hereto.

I claim as my invention:

1. A gas burner igniter and control circuit comprising a gas supply line, a gasr burner connected in said supply line, two gas valves connected in said supply lines on the supply side of said gas burner in series with said burner, an electrically energizable igniter, an energizing circuit for said igniter including a normally closed time delay switch and a llame detector switch opening by the heat of the burner flame, electrically energizable heater means for effecting opening of said time delay switch in a predetermined time delay interval, electrically energizable means for opening one of said valves, connected in series with said electrically energizable heater means for opening said time delay switch, and energized through said flame detector switch when closed, electrically energizable means for holding said valve open upon opening of said flame detector switch, electrically energizable means for opening the other of said valves, said electrically energizable means for holding said one valve open and for opening the other of said valves being connected inparallel and being energized through said time delay switch and remaining energized upon opening of said flame detector switch, whereby failure of the burner to ignite will effect opening of said time delay switch and closing of at least one of said valves.

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2. A safety gas burner ignition and control circuit comprising a gas supply line, a burner connected to said supply line, an electrically operated valve on the supply side of said burner, a second eiectrically operated valve in series with said lirst valve on the supply side of said burner, electrically energizable igniter means for igniting said burner, an electrical energizing circuit, a time delay switch, electrically energizable means connected in said energizing circuit to etfect opening of said time delay switch in a predetermined time interval, electrically energizable means for said igniter means connected in said energizing circuit through said time delay switch, individual electrically energizable means for opening said valves, the electrically energizable means for opening said lirst mentioned valve being connected in said energizing circuit in series with said electrically energizable means for opening said time delay switch, the electrically energizable means for opening said second valve being connected in said energizing circuit through said time delay switch, electrically energizable means for hoiding said first mentioned Valve open upon deenergizing of the electrically energizable means for opening said valve, a flame detector switch connected in series with said time delay switch and said electrically energizable means for energizing said spark igniter, said electrically energizable means for holding said iirst mentioned valve open being connected in said energizing circuit through said time delay switch independently of said ame detector switch, and said electrically energizable means for opening said rst mentioned valve being deenergized upon opening of said llame detector switch by ignition of the gas issuing from said burner.

3. in a gas burner igniter and control circuit, a gas supply line having a main gas burner therein and two valves connected in series in said gas supply line on the supply side of said main gas burner, electrically energizable igniter means for igniting said main gas burner, a transformer having a secondary connected with said igniter means for energizing said igniter means and having a primary, two main line conductors, an energizing circuit from said conductors to said primary including a time delay switch in series with said primary and a llame detector switch, said flame detector switch opening by the heat of the burner Iame, a heater coil for opening said time delay switch, a solenoid coil for opening a rst of said gas valves, an energizing circuit from said conductors to said solenoid coil through said heater coil and said flame detector switch, a solenoid coil for opening a second of said valves, a holding coil for said lirst gas valve for holding said gas valve open upon the deenergization of the solenoid coil for opening said valve, said solenoid coil for opening the second of said Valves and said holding coil being connected with said main line conductors in parallel and through said time delay switch, and said last mentioned solenoid coil and said holding coil being deenergized upon opening of said time delay switch upon failure of the burner to ignite,

whereby at least one of said valves will close upon failure of the pilot to ignite.

4. In a safety gas burner igniter and control circuit, a gas supply line having a gas burner connected thereto and having two valves connected therein in Series on a supply side of said burner, electrically energizable igniter means for igniting said gas burner, at least two main line conductors, an energizing circuit from said conductors to said igniter means including a time delay switch, a flame detector switch and a thermostatic switch connected in series across said conductors, a heater coil for effecting the opening of said time delay switch upon a predetermined time delay interval, individual solenoid coils for each of said valves for opening said valves, individual holding coils for each of said valves for holding said valves open, a rst of said solenoid coils being energized in series with said heater coil, said flame detector switch and said thermostatic switch, a second of said solenoid coils being energized in series with said time delay switch, said flame detector switch and said thermostatic switch, each of said solenoid coils being deenergized by opening of said ame detector switch by the heat of the flame of said gas burner, whereby a complete recycling of the circuit will be required to open said Valves upon a circuit failure, and said hold-ing coils being energized by said main line conductors in series with said time delay switch and said thermostatic switch and holding said valves open upon deenergization of said solenoid coils and accommodating closing of said valves upon a circuit failure.

5. ln a gas burner igniter and control circuit, a gas supply line, a gas burner connected in said gas supply line and two electrically operated valves connected in series in said gas supply line on the supply side of said gas burner, electrically energizable igniter means for igniting said burner, two main line conductors, an energizing circuit from said conductors to said electrically energizable igniter means includ-ing a time delay switch and a flame detector switch, said llame detector switch opening by the heat of the burner flame, a heater coil for opening said time delay switch, a solenoid coil for opening a first of said valves, and an energizing circuit from said conductors to said solenoid coil including said heater coil and said llame detector switch, a holding coil for holding said rst valve open, a solenoid coil for opening a second of said valves, an energizing circuit from said main line conductors to said last mentioned solenoid coil and to said holding coil through said time delay switch, said time delay switch opening upon failure of the burner to ignite and thereby deenergizing and effecting closing of at least one of said valves upon failure of the burner to ignite.

References Cited in the file of this patent UNITED STATES PATENTS 2,430,373 Strobel Nov. 4, 1947 2,479,779 lRay Aug. 23, 1949 2,812,806 Morrison Nov. 12, 1957 

